Machines for stitching cushions, mattresses and the like

ABSTRACT

Knot-tying apparatus comprising normally closed jaw members, means for advancing and retracting the jaw members whereby the jaw members can be moved into hook engagement with tying material in which a knot is to be tied, means for rotating the jaw members whereby a closed loop of the tying material can be formed about the jaw members, and means for actuating the jaw members so that they grip the tying material adjacent said closed loop, the jaw members being retractable to withdraw the jaw members from the closed loop and to pull the tying material where it is held by the jaw members through the closed loop to form and tighten a knot. A cutting edge is provided on said jaw members for cutting the tying material when the knot is tightened.

United States Patent 1 Nestenius MACHINES FOR STITCHING CUSHIONS,

MATTRESSES AND THE LIKE [76] lnventor: Nils Olof Nestenius, Muskotgan 21.

252 55 Helsingborg, Sweden 22 Filed: Sept. 14,1973

21 Appl. No.: 397.594

[451 May 13, 1975 3,410,589 11/1968 Nolt ..289/8 Primary E.\'aminerLouis K. Rimrodt Attorney, Agent, or Firm-Larson, Taylor and Hinds {57] ABSTRACT Knot'tying apparatus comprising normally closed jaw members, means for advancing and retracting the jaw members whereby the jaw members can be moved into hook engagement with tying material in which a knot is to be tied, means for rotating the jaw members whereby a closed loop of the tying material can be formed about the jaw members, and means for actuating the jaw members so that they grip the tying material adjacent said closed loop, the jaw members being retractable to withdraw the jaw members from the closed loop and to pull the tying material where it is held by the jaw members through the closed loop to form and tighten a knot. A cutting edge is provided on said jaw members for cutting the tying material when the knot is tightened.

3 Claims, 12 Drawing Figures PfZ TENTEU HAY 3 W5 SHEET 1 [if a PATENTEDHAYISIQYS q 883 sum 20F 41 FIG. 2

mimzu m I SiSTS 3,883 163 SHEET 3 A.

SHEET &0? A

PATENIE MAY 1 3197s MACHINES FOR STITCHING CUSHIONS, MATTRESSES AND THE LIKE This invention relates to knot-tying apparatus.

The invention is primarily concerned with knot-tying apparatus for use in machines for stitching cushions, mattresses, filter pads or other padded articles of the kind wherein, in operation, a length of tying material such as strong thread or cord is passed through the padded article at spaced points to form a loop of tying ma terial extending through the padded article and the ends of the tying material are then knotted together, such stitching operation producing a local depression in the padded article and imparting thereto a quilted effect. However, the invention also has application in other field where a knot has to be tied in a length of tying material, e.g., in baling machines and the like.

Although stitching machines of the kind aforesaid are well known, difficulties have been encountered in providing therein suitable means for mechanically knotting together the ends of a said loop of tying material after this has been formed, with the result that the knitting means has hitherto generally been unduly complex. The present invention has as its object to provide knottying apparatus which can be of simple construction and which is effective in use.

The present invention provides knot-tying apparatus comprising a pair of co-operating jaw members, a cutting edge carried by one of the jaw members, means for advancing and retracting the jaw members whereby the jaw members can be advanced into engagement with typing material in which a knot is to be tied, means for rotating the jaw members whereby a closed loop of tying material engaged by the jaw members can be formed about the jaw members, and means for actuating the jaw members whereby the jaw members can be caused to grip the tying material adjacent said closed loop, the jaw members being retractable by said advancing and retracting means to withdraw the jaw members from the closed loop and to pull that part of the tying material gripped by the jaw members through the closed loop to form and tighten a knot, said cutting edge serving to cut the tying material where it is gripped by the jaw members when the knot is tightened.

The jaw members may project substantially radially outwardly from one end of a rod or a shaft. One of the jaw members may be mounted on or formed integrally with the rod or shaft and the other jaw member may be pivotally connected to said one jaw member or to the rod or shaft. The pivotally mounted jaw member may be extended rearwardly beyond said pivotal connection to provide a rearwardly extending actuating arm engageable by a cam or other suitable actuating means for opening the jaw members, the pivotally mounted jaw member being spring biassed into closed position as by means of a spring extending between said actuating arm and said rod or shaft. With the jaw members projecting substantially radially outwardly from one end of a rod or shaft as aforesaid, the jaw members can be engaged hook-fashion with tying material in which a knot is to be tied and the rod or shaft then rotated about its longitudinal axis to rotate the jaw members so as to form a closed loop of the tying material about the jaw members.

The said rod or shaft may be the piston rod of suit.- able piston and cylinder means, e.g., a pneumatically- Operated piston and cylinder means, whereby the jaw members can be advanced to engage tying material in which a knot is to be tied, the piston rod being rotatable about its axis to effect said rotation of the jaw members to form a closed loop of the tying material about the jaw members. The piston and cylinder means may be pivotally mounted to enable the jaw members to make hook engagement with the tying material and to enable the jaw members to be subsequently withdrawn from the closed loop of tying material formed therearound and to pull the ends of the tying material held in the jaw members through the closed loop to form and tighten a knot as hereinbefore described.

The said cutting edge may be provided by a cutting blade carried by one of the jaw members, the arrangement being such that when the jaw members are retracted to form and tighten a knot, the effect of the retraction of the jaw members will be first to form and tighten the knot and then to cause the cutting blade to sever the tying material where this is held in the jaw members. Thus, for example, a cutting blade in the form of a tooth may be provided on one of the jaw members, e.g., the pivotally-mounted jaw member, at the outer extremity thereof, the cutting blade having a cutting edge which is directed inwardly of the jaw members and the arrangement being such that when tying material is held in the jaw members it will be held behind the cutting blade and will come into contact with the cutting edge thereof when the jaw members are retracted as aforesaid.

The invention also provides knot-tying apparatus according to the present invention when incorporated in a stitching machine of the kind hereinbefore described. Such a stitching machine may comprise a presser foot or the like for compressing a padded article in the region of where it is to be stitched, a needle or needles for passing a length of tying material through the padded article at spaced points to form a loop of tying material extending through the padded article, and means for holding the ends of the loop of tying material whilst the needle or needles is (are) withdrawn and the ends of the loop of tying material are knitted together.

In order that the invention may be the more readily understood reference will hereinafter be made, by way of example, to the accompanying drawings, in which:

FIG. 1 is a side elevation of knot-tying apparatus according to the present invention,

FIG. 2 is a side elevation of a machine for stitching padded articles,

FIG. 3 is a front elevation of the machine of FIG. 2, and

FIGS. 4a to 41' are diagrams illustrating the operation of a stitching machine according to FIGS. 2 and 3.

The knot-tying apparatus illustrated in FIG. 1 comprises co-operating jaw members I, 2, the jaw members being shown in open position to better illustrate the constructional features thereof although it will be understood that the normal position of the jaw members is closed. The jaw member 1 is formed integrally with the piston rod 3 of pneumatically-operated piston-andcylinder means 4, whilst the jaw member 2 is pivotally connected to the jaw member 1 by a pivot pin 5 and is extended rearwardly beyond the pivot pin 5 to provide a rearwardly extending actuating arm 6. The jaw member 1 has a groove or channel (not shown) in the underside thereof in which the jaw member 2 is received when the jaws are closed. The jaw member 1 also has a slot (not shown) in the rear end thereof through which the actuating arm 6 extends. A roller 7 is mounted on the actuating arm 6 and is adapted to be engaged by cam or other suitable actuating means (not shown) for opening the jaw members. A spring 8 ex tends between the actuating arm 6 and the piston rod 3 and serves to bias the jaw member 2 towards closed position.

At its outer extremity, the jaw member 2 is provided with an upwardly projecting tooth 9 having a sharp cut ting edge 10 which serves to cut-off surplus tying material when a knot has been formed.

The jaw member 1, the exterior surface of which is smoothly rounded, has a smooth outward projection 11 on one side thereof which serves to guide the tying material during the formation of a knot in a manner to be described.

In operation, and with the jaw members closed, the jaw members 1 and 2 are moved into hook engagement with the tying material to be knotted. The jaw members are retracted a short distance so that the tying material lies on either side of the jaw members in a V-formation and the jaw members are then rotated by rotating the piston rod 3 about its longitudinal axis to form a closed loop of the tying material about the jaw members, the projection 11 on the jaw member 1 serving, during the formation of the closed loop, to guide the tying material and ensure that the closed loop is formed around the throat portion of the jaw members, i.e., around the jaw members substantially in the region of where they first meet in the illustrated embodiment. When the closed loop has been formed the jaw members are opened by actuation of the actuating arm 6 and the rotation of the jaw members continued until the tying material beyond the closed loop has entered the open jaw members. The jaw members then close to hold that part of the tying material which entered the jaw members and the knotting means is displaced to the left in the aspect of the drawing so that the closed loop slips off the jaw members and the tying material where it is held in the jaw members is pulled through the closed loop to form the knot. Continued displacement of the jaw members to the left first tightens the knot and then re sults in the cutting edge 10 of tooth 9 severing the tying material where this is held in the jaws.

The machine for stitching padded articles illustrated in FIGS. 2 and 3 incorporates knotting apparatus ac cording to the present invention and comprises a frame 12 formed by a pedestal 13, a column 14 from the upper end of which extends a needle support 15 comprising beams 16, 17 and an upright 18, the uprights 19, 20 and 21 which, with the column 14, support a worktable 22. Upright 18 supports a sleeve 23 in which is slidably mounted a needle bar 24 having a holder 25 at the lower end thereof for a needle 26. The means for actuating the needle 26 is of conventional kind and accordingly has not been shown. A presser foot 27 (not shown in FIG. 3 in the interests of clarity) is connected by a connecting bracket 28 to a movable carriage 29 which comprises pneumatic cylinders 30, 31 and is movable vertically on rods 32 which extend between cross-members 33, 34 carried by the uprights 20, 21.

Mounted below the worktable 22 is a hook member 35 movable vertically on rods 36 carried by a bracket 37 mounted on upright 19, a catcher member 38 comprising a pneumatic cylinder 39 mounted on upright 19, and knot-tying apparatus 40 according to the present invention, the knot-tying apparatus (not shown in FIG. 2 in the interests of clarity) being of the kind shown in FIG. 1. The piston rod 3 of the knot-tying apparatus is rotatable by a pulley wheel 45, an endless belt 46 extending around the pulley wheel 45 and around a driven pulley wheel 47. The various mechanisms of the machine are actuated by a foot pedal 41 through suitable pneumatic connections (not shown).

In use, and referring to FIG. 4, a cushion 42 or other padded article to be stitched is placed on the worktable 22 and the presser foot 27 is lowered by partially depressing the foot pedal 41 so as to locally compress the cushion 42 as shown at 43. The foot pedal 41 is then depressed completely to initiate the automatic sequence of operations illustrated in FIG. 4. First, FIG. 4a, the needle 26 threaded with tying material 44 passes downwardly through the compressed portion of the cushion 42. The tying material 44 is engaged and drawn downwardly by the hook member 35, FIG. 4b. The catcher member 38 moves inwardly and gathers the tying material 44 from the hook member 35, FIG. 40. The needle 26 is withdrawn through the cushion 42 and the hook member 35 is returned to its initial position, FIG. 4d. The worktable 22 and presser foot 27 are moved horizontally to displace the cushion 42 sideways by about 10 mm. with respect to the needle 26, FIG. 4e. The needle 26 is again passed downwardly through the cushion 42, FIG. 4f. The tying material 44 is again engaged and drawn downwardly by the hook member 35 and at the same time the tying material 44 is cut adjacent the presser foot 27 by cutting means (not shown) incorporated in the presser foot and the needle 26 retracted, thus leaving a loop 44a of tying material extending through the cushion 42, FIG. 4(g). The knottying apparatus 40 is moved into engagement with the ends of the loop 44a of tying material and the jaw members l, 2 (FIG. 1) actuated as previously described to form a knot, FIG. 4(h). The knot-tying apparatus 40 is retracted to tighten the knot and sever the loose ends of the tying material, FIG. 4i. Finally the presser foot 27 is returned to its initial raised position to release the cushion 42.

What is claimed is:

1. A machine for stitching padded articles, comprising a presser foot for compressing a padded article in the region of where it is to be stitched, needle means for passing a length of tying material through the padded article at spaced points to form a loop of tying material extending through the padded article, means for holding the ends of the loop of tying material, and means for tying a knot in the ends of the loop of tying material, the knot tying means comprising a pair of cooperating jaw members, means for advancing and retracting the jaw members whereby the jaw members can be advanced into engagement with the ends of the loop of tying material, means for rotating the jaw members whereby a closed loop of the ends of the tying material can be formed about the jaw members, and means for actuating the jaw members whereby the jaw members can be caused to grip the ends of the tying .material adjacent said closed loop, the jaw members being retractable by said advancing and retracting means to withdraw the jaw members from the closed loop and to pull the ends of the tying material whereby they are gripped by the jaw members through the closed loop to form and tighten a knot, said jaw members comprising a cutting edge formed thereon for cut- 6 ting the ends of the tying material where these are tion which has the said cutting edge formed thereon. gnpped m the Jaw members when a has been 3. A machine according to claim 1, wherein said upformed and tightened.

2.. A machine according to claim 1. wherein at least one of said jaw members has an upstanding tooth por- 5 standing tooth is formed on the movable jaw member. 

1. A machine for stitching padded articles, comprising a presser foot for compressing a padded article in the region of where it is to be stitched, needle means for passing a length of tying material through the padded article at spaced points to form a loop of tying material extending through the padded article, means for holding the ends of the loop of tying material, and means for tying a knot in the ends of the loop of tying material, the knot tying means comprising a pair of co-operating jaw members, means for advancing and retracting the jaw members whereby the jaw members can be advanced into engagement with the ends of the loop of tying material, means for rotating the jaw members whereby a closed loop of the ends of the tying material can be formed about the jaw members, and means for actuating the jaw members whereby the jaw members can be caused to grip the ends of the tying material adjacent said closed loop, the jaw members being retractable by said advancing and retracting means to withdraw the jaw members from the closed loop and to pull the ends of the tying material whereby they are gripped by the jaw members through the closed loop to form and tighten a knot, said jaw members comprising a cutting edge formed thereon for cutting the ends of the tying material where these are gripped in the jaw members when a knot has been formed and tightened.
 2. A machine according to claim 1, wherein at least one of said jaw members has an upstanding tooth portion which has the said cutting edge formed thereon.
 3. A machine according to claim 1, wherein said upstanding tooth is formed on the movable jaw member. 